Linkert setup and tuning

[choppercopper1]

Just finished putting my M51 back together. Soaked it and rebuilt it with one of those kits with all the springs, balls and gaskets. This carb came off my 45 flatty. Having problems with setting it up. Waiting for my 45 book to come in the mail so I have questions. Set the carb up and the bike starts and runs BUT it will not run on an open choke. Intake leak??? Turned both rods till I was blue in the face and still can't get it right. Anyone have a secret that they would like to share with me on making this thing right or any ideas on where to check next. Going to pull the manifold off and see if there is any leaks. I know I will try the water around the nipples while the motor is running first trick. :(
Thanks in advance!!!!

[Pegtooth]

Can have the Victory Linkert book open in front of me if you want to call.(860)304-8869

[Rudehog]

Calling DrJett!! DrJett wherefore are thou!


Fuck that sounds gay

[Donzzilla]

Sucess with carb's is spelled MIKUNI. find one that fits, get the Sudco tuning book, spend an afternoon on it and a lifetime of riding it.

Just my oppinion, Don

[Trent]

Linkerts are great carbs.. Dont give up. I love them.

Did you clean the body GOOD?

Start at the beginning and work out from there.

[Destralo Roach]

Use carb spray to check for intake leek, and make shure the shaft's and bushings are new.......Roach.

[Nelson]

From what I hear, intake leaks are the biggest culprit of bad running Linkerts. I've never actually worked on a flathead, but since its got those plumbing style intakes its probably got those two sleeves in there. Make sure those are new or in excellent condition.

If you cant get the intake to seal, even with new sleeves, use a little copper RTV at the end of the sleeves (on both ends). This is not a permanent fix though, cause gas will deteriorate the RTV stuff. I sealed up the intake leak on my knuck this way and its been running tip-top for almost a year now.

After you think you have the intake all sealed up, make this intake leak "tool", its worth it:

Take off of the carb and get a 1/4" steel plate and make a "cover" that goes over the hole on the intake where the carb was. Mark the mounting holes from the intake onto the steel plate.

Drill out the mounting holes on the steel plate. Now you can cover that hole perfectly with this plate and mount it to the intake. Then you put a gasket between the plate and the intake. Take the plate back off and drill a hole in the center of the plate and hook up an air fitting so you can hook up an air compressor to it. You absolutely need to have a working regulator on your compressor to do this.

Next, run air to it but only a few pounds. I think around 5lbs or less should perfect, nothing more. Then spray some soap&water on the intake fittings to check for leaks. This is how I got mine to seal all perfect. You see exactly where the leak's coming from.

Clean the FUCK out of that carb! Get crazy! I like using carb cleaner first then brake clean. I go through cans of that shit like crazy. Then use compressed air.

Or you can run a Mikuni on the flathead. Then maybe just pull the flathead out and run a Honda CB motor while you're at it.

I hope this all makes sense cause I have a hard time explaining tech shit!

[Destralo Roach]

Ya, talk about plumbernut intakes! I was going to sturges back in the late 80's on my 48 pan, went over the grapevine and made it into Fresno, burnt a hole in the front piston, rebuilt it and turned round went back to dago, so mutch for that! (maybe one off these years I'll make it yet!).........Roach.

[Nicke]

The most simple way to check for intake leaks is to spray starting gas on/around the intake when the motor runs.

If it revs up, you got a leak.

[45.]

Linkert adjustment with the carb mounted the High Speed needle will be to the left, low speed needle to the right

1. turn both high, and low speed needles all the way in (clockwise) be gentle, stopped is all the way in

2. Back out the low speed needle 2 turns

3. Back the high speed needle out 1 1/2 turns

The mixture will be fat

Start the motor, after choke lever has been moved to open position, and the motor is warmed to normal heat:

1. adjust low speed 1st, turn the needle in (clockwise) one notch at a time (spring loaded detents you can feel the clicks) until it gets so lean the motor misses; back needle out 7 to 10 clicks, or until the motor runs without missing with the throttle closed, and spark advanced.

2. adjust throttle stop screw (idle screw) as needed to get the motor to idle (turning the screw clockwise increases idle RPM)
Don't set your idle real low, ya it sounds cool, hard on the lower end, and hard to start. Before adjusting the idle screw be sure the throttle cable has enough slack to allow adjustment

3. High speed needle "one way to get high speed adjustment is to retard spark halfway. then blip the throttle open quickly. if the motor backfires or spits through the throat the mixture is too lean and the high speed needle should be backed out (counter clockwise) another 1/2 turn. if the motorhokes when the throttle is opened the mixture is too rich, and the high speed needle should be turned in (clockwise) 1/2 turn. keep playing the game till the motor runs without spitting, or choking.

lather rinse repeat 1 through 3 until it runs well without spitting or choking when throttle is blipped.

Alternatives to Linkert:

SU off a 50 's era MGA sportscar

Feeling Roadwarrior? Lake Injector, great one for flame throwing

Toiletson I know folks that swear by them, I had a fire on a sled due to the flush of a toiletson.

Bendex, ran quite well.

To run any of these you will have to, or have someone, machine an adapter to the linkert manifold flange, and the flange of the carb of your choice

Should you stick with Linkert, buy a brass float, if you do not already have one

32 tooth motor sprocket is optimal for a 45 solo if you can find one

[sLowrider]

Do a search for 'Cotten' seals on the forum on www.flatheadpower.com. US made intake seals and far superior to the brass ones. I run a 32mm Amal on my 45 - works great - but the Linkert is easy to set up if you've got no intake leaks.

[choppercopper1]

Thanks guys!!!
I am going to keep the Linkert. I love the way they look. I think that the intake is leaking due to not being able to open the choke all the way. The guy that I bought this from might have just pieced this together so I have no idea what shape the intake seals are in. As far as cleaning the carb. This thing has been totally taken apart and dipped in a gallon bucket of carb cleaner that I get at the car store. Stuff is excellent. The carb came out looking new. I replaced the float with a brass one along with all the other parts. Going to make a leak tester like Nelson said and see what happens. Hopefully after I put everything back together and tune like 45 said it should run.
Thanks again guys for the much needed info!

[Nelson]

...I replaced the float with a brass one along with all the other parts. Going to make a leak tester like Nelson said and see what happens. Hopefully after I put everything back together and tune like 45 said it should run.
Thanks again guys for the much needed info!


If I were you, I'd toss the brass float. Most of the time they dont actually float that well. In fact they tend to leak internally. The brass floats are of poor quality and actually weigh 3 times more than the stock float that the Linkerts used to come with. They do sometimes work though, that is true.

The best float you can get on this entire planet is Cotten's floats. They're pricey, but worth it. I think someone posted how to find him in this thread. If you get one of his floats, be careful with it. Its delicate.

I hear his intake seals are excellent too. I never got around to send him my intake to have him set it up.

Another nice item to have (if you're going to screw around with the float) is to have a nice, new needle and seat. Dont use the needle with the rubber tip. The rubber will go to shit.

Cotten should be able to tell you where to get a good needle a seat (you have to use/buy them as a matching set, dont mismatch them from a stash you may have).

I dig fact that you're trying your best to get your Linkert working. Dont give up. And as they say... if you ask 10 different people...

[Creepinogie]

Cotton at Liberty cycle in Illinois is one of the best Linkert guy's around. You should use one of his floats. One thing you need to be aware of is the float in Linkerts is not supposed to be centered in the bowl. if it is, it may hang up. It needs to be slightly off to one side. I can't remember off the top of my head which side it should be off to. this is a very common mistake. You may not be getting the proper amount of gas into the bowl and are compensating by running your bike with the choke closed. DO NOT USE A MIKUNI - THEY CAN BE MADE TO WORK BUT ARE NOT THE OPTIMAL CARB FOR V-TWINS.

Another thing about Linkerts is that quite often they are pieced together from different models. All the parts "fit" but they are not designed for one another. ie, mismatched needles, venturis,etc.

[oldspeed]

If you determine that the intake is sucking air, spray any flamable like brake cleaner and or wd40 around the manifold nuts and see if the engine picks up speed. If it does don't be afraid to loosen the cly. base nuts and you can rotate the the cly'nders more than you might think to get the surfaces in line to seal well. Keep the linkert they are simple and intake leaks are not that hard to solve.

[flattracklarry]

If I were you, I'd toss the brass float. Most of the time they dont actually float that well. In fact they tend to leak internally. The brass floats are of poor quality and actually weigh 3 times more than the stock float that the Linkerts used to come with. They do sometimes work though, that is true.

The best float you can get on this entire planet is Cotten's floats. They're pricey, but worth it. I think someone posted how to find him in this thread. If you get one of his floats, be careful with it. Its delicate.

I knew about avoiding rubber-tipped needle/seats. I have a stock all-brass one in my Linkert. What's the deal with the Cotten float? What is it made of?

[Creepinogie]

Cottons floats are hand cut on his lathe from some sort of foam. They are modern fuel proof but you need to run the top-hat looking brass nut that formerly attached the cork float to the needle assembly. But he can supply that too. The problem with the brass floats is that you need to set the height different because they are heavier and sink further than the old cork floats. And there's at least two different manufacturer's of the brass floats with two different weights and therefore two different settings. I ran a brass float with no problems for over 10 years but you might have to play around with the float setting. I think I paid something like $45 for my "cotton float" The guy's name is Tom Cotton at Liberty Cycle in Layton Ill. He is well known in the Indian and antique HD community.

[tombat]

I have heard them (linkerts) referred to as "Milwaukee sewer pipes" but that doesn't make them bad, just a challenge! Also, from my experience "Cotten = genius" Have fun.
Tombat

[sLowrider]

Also when your carb's off check your intake nipples. They work loose with time. New ones are pennies. I can't recall if you can drill out the rivets with the jugs still fitted but it isn't a big job to remove them. Fit new nipples real tight. I don't bother riveting them - I drill out the rivet holes very carefully (cast iron!), drill through the nipple, tap and fit 3/16" locating screws with Loctite. I've heard lots of ideas about sealing the nipple to cylinder thread - personally I use copper grease to allow me to disassemble them if needs be.

[choppercopper1]

OK did a search on FHP site and did some reading. Made the tool to check for manifold leaks. Worked EXCELLENT! Found the problem, Hopefully. The rear intake is leaking as well as the rivit in the jug. Didn't have time to take it apart yet but at least I k ow where I stand. Thanks Guys for all the help.
http://img513.imageshack.us/img513/2549/1000514xt4.th.jpg (http://img513.imageshack.us/my.php?image=1000514xt4.jpg)
http://img296.imageshack.us/img296/7207/1000515ov7.th.jpg (http://img296.imageshack.us/my.php?image=1000515ov7.jpg)

[Dragon]

Bump for some good tech.